Large scale roadside mowers are commonly attached to tractors or other suitable vehicles. Heavy roadside mowers are sometimes mounted directly behind tractors. Such mowers are either suspended from the vehicle or have integral wheels which support the mower above the ground from beneath. Mowers such as these are appropriate when it is possible to drive the tractor over the ground which is to be mowed. In many instances, however, the ground to be mowed cannot be negotiated, particularly by wheeled vehicles.
Roadsides or highway medians are typically difficult for wheeled vehicles to travel over, for a variety of reasons. For instance, roadsides are often steep or irregular. In addition, access by wheeled vehicles is frequently prevented by guardrails or other structures alongside roads. Furthermore, roadsides are often strewn with rocks, holes, or other obstacles, precluding access by wheeled vehicles or by mowers supported from beneath by wheels or runners.
Because of the inaccessibility of roadsides to conventional mowers, mowing devices have been attached to booms which extend laterally from a mobile vehicle such as a tractor or road grader. Such booms suspend the mower above the ground to be mowed. The booms are usually articulated to allow selective placement of the mower. In addition, angular orientation of boom-mounted mowers is adjustable to conform to varying roadside slopes.
Varying the angular orientation of a boom-mounted mower allows convenient mowing of sloped roadsides. However, mowing such sloped roadsides consumes a great deal of time and effort. This is particularly true in instances where the roadside has an irregular contour, such as a ditch. At least two mower passes are usually required to mow a ditch having two oppositely sloping sides. During the first pass, the mower is inclined parallel with one sloped side of the ditch. During the next pass, the mower is inclined parallel with the remaining sloped side.
Ditches are not the only form of irregular contour found alongside roadways. For instance, a highway shoulder may be humped. It may extend horizontally away from the road for a short distance before sloping upward or downward. In such cases, multiple passes are required to adequately mow the different roadside slopes. In addition, a roadside contour rarely remains constant, thus complicating the mowing process.
The invention described below simplifies the task of mowing irregular roadsides, and is particularly advantageous for mowing ditches. In most cases the invention eliminates the need for multiple passes. The invention allows mowing time and expenses to be significantly reduced, such as by nearly one half, while achieving acceptable or improved results.